77K5. The IronMaiden...9/2 headed for Blazer Bash 20!

[76zimmer]

Here is a pic of the holes in the bellhousing area. I got a welder dude repairing these now.

And before taking this apart, your supposed to check the input, and output units for endplay according to the GM service Manual.
My input was about .060 to much endplay, which confirms to me that this thing has been apart before....
I'll need to changed the thrust washer between the front pump, and direct drum to correct this.


Here is the GM Service Manual I bought when I bought my 85 truck new.

 

[76zimmer]

I also got the heads back from my head guy, and a bunch of parts for them.....

Valves and springs on heads.....

This intake has been port matched to the 781 heads. Compare to the intake when I first got it.

Before:

After portmatching:

And the rest of the parts for the top end..

 

[AJMBLAZER]

Any idea what put the holes in the bellhousing like that? Crazy.

I have a '86 manual for Big Ugly. Great stuff...except for the random typos. Need to get a '89 set for The Blazer.

 

[76zimmer]

I don't have a clue AJ....in addition, you can see where someone broke off a bolt from the pan, in the case right by the modulator, and just took a drill and made a new hole at an angle to the original. Someone also tried to pry out the front pump, from the bottom of the case, and broke some of the casting. It looks like it isn't in a critical area, but again this stuff I bought has been abused by a bunch of Bubba's. Hopefully the 205 is in good shape....I guess I'll see about that when I get to it. I picked up the trans case today, and will show the repairs on it tomorrow.

 

[AJMBLAZER]

Random, but did you say you have a deep pan you aren't using? Big Ugly has a TH400...

 

[76zimmer]

I do have the factory deep steel pan AJ, take a look in the above pics.....its a little beat up more than it shows there.

 

[AJMBLAZER]

Ah, probably the same pan as I have then.

 

[79rustyk10]

I have a TH350 with a hole in it like that. It was from the cab supports above the front cab mounts rusting away, and one of the bolts that holds the transmission hump to the floor rubbing through the case. Mine only has a hole on the drivers side though.

That truck was epic rusty. There was no and by no I mean none of the factory floorpans left on the drivers side, and all the cab supports rusted away. There was a 2" gap at the bottom of the door and the door was binding on the fender up top.

whats even funnier was that the drivers rocker panel fell off when I was parting it out.

 

[BGKYK5]

I don't have a clue AJ....in addition, you can see where someone broke off a bolt from the pan, in the case right by the modulator, and just took a drill and made a new hole at an angle to the original. Someone also tried to pry out the front pump, from the bottom of the case, and broke some of the casting. It looks like it isn't in a critical area, but again this stuff I bought has been abused by a bunch of Bubba's. Hopefully the 205 is in good shape....I guess I'll see about that when I get to it. I picked up the trans case today, and will show the repairs on it tomorrow.

Yowser, maybe time to find a new case?

 

[76zimmer]

I have a TH350 with a hole in it like that. It was from the cab supports above the front cab mounts rusting away, and one of the bolts that holds the transmission hump to the floor rubbing through the case. Mine only has a hole on the drivers side though.

That truck was epic rusty. There was no and by no I mean none of the factory floorpans left on the drivers side, and all the cab supports rusted away. There was a 2" gap at the bottom of the door and the door was binding on the fender up top.

whats even funnier was that the drivers rocker panel fell off when I was parting it out.

That could very well be the case....2 holes right about where the transmission access cover would be....

the welder dude plugged them up for me, and also put some filler metal in a few spots to redrill and tap new holes. One on the pan rail, and the other where the convertor cover bolts up. And he only charged me $40 for these repairs....good dude.

Bellhousing plugged holes:

Pan Rail repair:

Some pics of broken internal casting. It doesn't appear to be a structurally important part, as the shifter shaft threaded hole is intact, and nothing attaches to the broken area. I'm not even sure how much of that area is missing.

 

[76zimmer]

I also took a few pics of the D60 repair in progress.

the new kingpin threaded into the modified repair sleeve.

the upper kingpin hole that still needs to be drilled out to accept the modified repair sleeve:

 

[76zimmer]

The T400 case is repaired and cleaned inside and out, with a fresh coat of chassis black.....

I use mineral spirits to clean, then rinse with brake cleaner, followed by a good strong shot of compressed air.

The pump and forward clutch disassembled, cleaned and inspected:

The clutch discs, and steels from the forward clutch pack, and the 3 piston seals from the forward clutch piston:

I like to take one sub-assembly at a time and rebuild it, then move on. Its easier to keep track of whats going where that way.
I follow the GM service manual, as there is many things to check throughout the rebuild process, and its pretty thorough with pics too.



Now I just have all these to disassemble, clean and inspect, before starting component installation:

These are some of the upgraded parts I'll be adding
The Coan reverse pattern manual valve body with engine braking:

The 34 element direct drum, and sprag assembly:

The aluminum finned pan:

Tomorrow my Dad is coming out to help again....I really like to have him just hang out, and B.S. in the shop. We used to do the same thing some 35 years ago. I guess we'll see if we can get anything done....

 

[76zimmer]

I had trouble getting the recommended clearance of .050 on the clutch pack for the forward drum, and called COAN transmissions about it, the asked what the piston type was....Its stamped steel....he said those were a weaker unit than the cast aluminum ones, and that a cast aluminum one would fit the clutch pack "right". So I ordered two of them, one for the forward clutch, and one for the direct clutch.
The stamped steel piston is thinner, and requires a wavy spacer to make up the distance, where the cast one is one piece.
They also talked me through a couple other questions I was having about the pump sealing rings, and the thrust washer clearance between the pump and forward housing. Good to have an answer man handy when you need em. I really like dealing with these guys.


So the stamped steel piston and spacer ring look like this:

In addition the reaction carrier housing had these waves in it, that was caused by the old band. Coan said it would be ok to run it as is, with a new band, and to check the pump booster bore, to make sure it wasn't sticking. Evidently that supplies pressure to the apply pin for the rear band.

The reaction drum surface:

 

[76zimmer]

I'm trial assembling some components for the doubler setup, and went to put in the T400 32 spline short rear output (from ORD), and its the same as what is in the trans already. From my understanding this T400 I have was supposed to have a 32 spline long output shaft, because of the round pattern 205, with the 4" adapter between them. This is not the case.
Anyhow, I talked with Jon at ORD about returning that item, as its not needed.

I have all the major components cleaned and partially assembled, but need to wait for those pistons from Coan...hopefully monday?

The T400 mostly has a 16 (or less) element direct drum and sprag assembly. This is one part that can be improved upon. The 34 element sprag gives a lot more holding power than the other sprags. This upgrade cost about 125$ for the drum and sprag.

The weaker stock sprag:

The stronger new 34 element sprag and direct drum units:

And there is 3 of these thrust bearing assemblies in the rear part of the trans.....they are all different, but similar..... If you take your 400 apart, make sure you know where these each go, and in what position the thrust bearing races go against the shafts. Some enclose the bearing, and some have the races both going in the same direction.

 

[boggerless]

MR.Hardcore. cool Dave., i like this part

 

[76zimmer]

Ha Ha....yeah I thought that was a nice touch too Daryl....


I got the 203 separated today, and will change the input tomorrow from the 27 spline to the 32 spline.

I got the shafts from ORD lined up.
Do I have these right?

T400, 203 input, 203 output, and 205 input.

I need to call ORD when I get these figured out.

 

[crawdaddy]

That looks right. I just put mine together this weekend. I didn't have to change my input, but the rest of it should be easy compared to the tranny work you have been doing.

Now it is time for the crossmember

 

[76zimmer]

I was just concerned that I got the right ones.....i.e. are they all going to be compatible? I've already got the same T400 output in the trans as whats on the table.
My combo is T400-32 spline out/T400-203 adapter/203 with 32 spline input/doubler setup for a round 205/205 with the required short 32 spline input.
I'll find out soon if these are all as compatible as I think they are.
And as far as the T400 goes, I'm glad I got some expert advice through Coan, and a Gm service manual on the bench.

 

[76zimmer]

I got the 203/range box done today....I had to change the input shaft to match the 32 spline output of my T400, and while I had it apart, I cleaned it out good inside and out. The shifter fork was binding up and wouldn't engage the forward gear. After checking it out, the gear selector (slider) wasn't lined up with the forward gear engagement teeth. I ended up grinding the tip of the fork so it would slide farther up into the fork lever and let the slider be centered on the forward gear engagement teeth. After putting the range box on the transmission, it shifts from high to low range nicely now.

A big thanks to Brett (SweetK30) for his tech article on the 203/205 doubler build.....it was a big help, and I'm sure will be for the 205 also.


The 203 (with adapter from Brett) on the T400 with the ORD adapter, and the new 205 input shaft hanging on the end of it:

The 205 to be rebuilt yet:

I got my new T400 pistons today, and went to a local trans shop to get an intermediate clutch spring retainer (another cheap part GM through in there that broke).
He ended up giving me an older style aluminum piston, that has the spring pockets cast in, so I can get rid of the cheap stamped steel junk. Freebie, who doesn't like that?
My D60 should be done tomorrow. I checked out the kingpin, but didn't have my camera when I went to see him today.....he said he'd have it put together before I could get there tomorrow, so I'll try to get a pic of the repaired kingpin if I can. He said it will be as strong as new.......Nice.


.

 

[crawdaddy]

That tranny pan looks awesome on there